Simple and efficient method for the extraction, isolation, and purification of peroxidase enzyme from wheat bran

Peroxidase is an industrially important enzyme with a broad range of applications. In this study, the extraction, isolation, and purification of peroxidase was conducted with wheat bran as a feedstock. Several commercially available buffers (K₂HPO₄, Na₃PO₄, CH₃COONa, and Tris-base) were explored for the extraction of peroxidase from wheat bran. Of the tested media, sodium acetate buffer gave an excellent performance and displayed maximum protein (0.44 mg mL⁻¹) and enzyme activity (28 U mL⁻¹). A process optimization study was also conducted to obtain the maximum protein concentration and enzyme activity. The intensified process provided 1.39 mg mL⁻¹ protein concentration with 90 U mL⁻¹ enzyme activity with specific enzyme activity of 135.8 U mg⁻¹. Crude enzyme was purified using a three-step process: (a) precipitation, (b) ultrafiltration, and (c) chromatographic purification. Commercially available strong and weak ion exchange resins, with different surface properties, were tested for purification. The weak anion exchange resin showed an excellent performance for maximum binding of peroxidase. Adsorption study investigated the best fit model of Freundlich isotherm with maximum binding capacity of 54 mg mL⁻¹. Overall, purification provided peroxidase with a protein concentration of 1.24 mg mL⁻¹ and 727.58 U mg ⁻¹ specific enzyme activity with purity increased by around ~6.6 fold. The reported process provides a simple and efficient method for the extraction and purification of peroxidase enzyme from wheat bran for its efficient valorization.